Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D17/00—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles
  • F28D17/005—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles using granular particles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D17/00—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles
  • F28D17/02—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles using rigid bodies, e.g. of porous material

Definitions

• the present invention relates to a method of reheating gas in a regenerator with a mass of heat accumulation made up of bulk material arranged in a ring between two coaxial cylindrical grids, a hot collection chamber, surrounded by the internal hot grid, for the hot gases and a cold collection chamber, enclosed between the external cold grid on the one hand and the external wall of the regenerator on the other hand, for cold gases, as well as a regenerator of this type.
• the hot gases respectively the cold gases are led in the radial direction through the mass of heat accumulation, unlike otherwise usual air heaters, and in fact during the heating phase, from the chamber hot collection inside the regenerator to the external cold collection chamber, and in the opposite direction during the cold blowing of the regenerator.
• the gases to be heated can also be gas mixtures, which also contain parts of vapors, in particular water vapor.
• the object of the invention is therefore to improve the process mentioned in the introduction as well as the regenerator described above, by avoiding the drawbacks caused by the chimney effect and in particular by increasing the power of the regenerator for a height significantly less construction of it.
• this objective is achieved by the fact that the increase in the pressure drop during the heating phase is at least 5 times as great as the product pgH, in which H is the height of the regenerator , p is the density of the gas at a temperature of 20 ° C and g is the acceleration of gravity, and that the gas flow is at least 300 m 3 N / hm 2 of surface of the hot grate at normal pressure .
• the cold phase that is to say the cold blowing, is carried out with an overpressure.
• the flow of gas to be heated increases in the P / P 2 ratio, without the heat transfer being degraded.
• the flow rate can reach 5000 m 3 N / hm 2 , respectively 2500 kW / m 2 .
• a regenerator having a grid area of 20 m 2 , it is possible to produce a flow of hot wind of 100,000 m 3 N / h.
• the grain size of the bulk material is chosen to be less than 15 mm.
• the heating phase when operating at partial load, is carried out at full power, and breaks are observed after the cold blowing phase.
• This implementation of the process makes it possible to work with the desired constricted power, and the thermal equilibrium of the two phases is then established by the breaks after the cold blowing, and also to use for heating the regenerator a burner which has only a very limited range of adjustment, unlike the burners used until now in conventional wind heaters.
• the other objective fixed to the invention is, in a regenerator intended for the implementation of the method, achieved by the fact that the outside diameter of the annular mass of heat accumulation is at most double the inside diameter .
• the regenerator is heated with a premix burner.
• FIG. 2 An exemplary embodiment of the burner is shown in FIG. 2 and will be explained in detail below.
• the regenerator 1 intended for implementing the method of the invention has an enclosure 2 having the shape of an upright cylinder, which can for example be supported by means of pillars 3.
• the interior space of the enclosure 2 is essentially divided by two grids 4 and 5 of cylindrical shape and arranged concentrically at a distance from one another, into a hot collecting chamber 6 internal cylindrical, an intermediate annular chamber 7 containing the mass of heat accumulation consisting of bulk material, and a cold external annular collection chamber 8 formed by the wall of the enclosure 2 with the grid 5.
• inlets 10 are provided for the heating gases, which are produced by a premix burner 11, which in turn is supplied by a gas mixing tube - air 12.
• the hot internal collection chamber 6 ends in the upper region of the enclosure 2 of the regenerator 1 by a hot wind outlet 13, the external collection chamber 8 is connected to a chimney 14 for evacuating gases from which the heating gases can escape after they have passed through the heat storage agent in the intermediate chamber 7.
• the gas-air mixing tube 12 is connected to a fan 15, which produces both the air for the heating phase and for the cold blowing phase. In the heating phase, the air is led through the gas-air mixing tube 12 and mixed with heating gas, which has been introduced by the gas injector 16 into the gas-air mixing tube 12.
• valves 17, 18 and 19 are closed, the valve 20 as well as the outlet 13 are instead open, so that the cold blowing phase can then begin.
• the open fittings are closed again and the previously closed valves are opened, so that the heating phase can start again.
• the bulk material of the heat accumulating mass consists of a charge of granules with a grain size which does not exceed 15 mm, and the outside diameter of the annular heat accumulating mass is not greater than double the inside diameter.
• This minimum flow corresponds to a power of 300 m 3 N / hm 2 .
• the S profile of the temperature is more and more clearly raised.
• a particularly advantageous operating point has appeared for a flow capacity of 1000 m 3 N / hm 2 , a pressure drop of 1000 to 1600 Pascal.
• An increase in the flow rate up to 2000 m 3 N / hm 2 is possible without reducing the heat transfer, taking into account a pressure drop from 3000 to 5000 Pascal.
• This power limit is applicable to walking at normal pressure.
• the operation under increased pressure has shown the surprising result, that the flow rate can be further increased, in fact in proportion to the absolute pressure, without the heat transfer data being degraded. If, for example, a blast furnace wind at 5 bar is produced, the flow rate can reach 5000 m 3 N / hm 2 , respectively 2500 kW / m 2 . It is thus possible to produce a flow of hot wind of 100,000 m 3 N / h with a regenerator having a grid surface of 20 m 2 .
• regenerator Since heating of the regenerator is in fact generally carried out at normal pressure, three generators must be heated simultaneously, so that a total of four regenerators are required to ensure continuous operation for the production of hot gases. These regenerators only have a diameter of 4 m for a height of 5 m, while the air heaters of the same power used until now have a diameter of 8 m and a height of 30 m.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• Dispersion Chemistry (AREA)
• Chemical & Material Sciences (AREA)
• Drying Of Solid Materials (AREA)
• Air Supply (AREA)
• Furnace Details (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
• Air Bags (AREA)
• Gas Burners (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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• 1992
  • 1992-10-29 DE DE4236619A patent/DE4236619C2/de not_active Expired - Lifetime
• 1993
  • 1993-10-19 CA CA002126993A patent/CA2126993C/fr not_active Expired - Fee Related
  • 1993-10-19 WO PCT/FR1993/001025 patent/WO1994010519A1/fr active IP Right Grant
  • 1993-10-19 KR KR1019940702048A patent/KR100317968B1/ko not_active IP Right Cessation
  • 1993-10-19 ES ES93923585T patent/ES2202314T3/es not_active Expired - Lifetime
  • 1993-10-19 US US08/232,064 patent/US5547016A/en not_active Expired - Lifetime
  • 1993-10-19 JP JP6510757A patent/JPH07502804A/ja active Pending
  • 1993-10-19 EP EP93923585A patent/EP0617785B1/de not_active Expired - Lifetime
  • 1993-10-19 AT AT93923585T patent/ATE247271T1/de active
  • 1993-10-29 CN CN93119561A patent/CN1072793C/zh not_active Expired - Fee Related
• 1996
  • 1996-04-16 US US08/639,005 patent/US5690164A/en not_active Expired - Lifetime

Non-Patent Citations (1)

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